Dissolution testing is an analytical technique used to determine the rate at which a pharmaceutical dosage form, usually a tablet, capsule, or transdermal, dissolves into a given media over time. Generally, the release (or dissolution), of the Active Pharmaceutical Ingredient (API) from the dosage into the media is measured for a specified duration under controlled conditions. This measurement is made either by performing in situ measurements with fiber optic probes, or samples are taken at predetermined time points, filtered, and measured on an analytical instrument, most commonly, an HPLC or in-line UV analyzer. The release of API may be rapid, (within minutes), for immediate release dosage forms, or may be significantly longer, (occurring over hours or weeks) for controlled/modified release formulations.
Conventionally constructed dissolution apparatus most commonly employ a solid base; a vessel manifold mounted on said base which is connected to a circulating, temperature programmable water bath; and a stirring element, which is rotated (or reciprocated) within the vessel. Automated dissolution testing systems generally contain additional dosage, media, and sample handling systems. Requirements for a dissolution testing apparatus are provided in United States Pharmacopeia (USP), Section 711, Dissolution (2000). The underlying process of dissolution testing and apparatus for performing such testing are known in the art.